Unless I am mistaken, aren't Adalind's powers dwindling back? Eve sensed her powers returned and that they weren't at full strength. And there's the matter that she's at the point where she'd rather not have them at all and uses them in an emotionally changed moment like with Tony and Renard when he tried to force himself on her. Using her powers for everything isn't a reflex anymore. Eve was stronger than Adalind even on her best day, she didn't have any qualms taking Conrad on and she's not being threatened through her children.
Sean may have put her in this fake relationship but the cursed ring is keeping her there (for now). I think Sean would still need Adalind and their fake relationship because clearly they are/were aiming much higher than just him being mayor of Portland but that's story is over with Conrad's death it seems. I think they initially thought she'd come willingly until they realised she'd never leave Nick and so resorted to force (and Diana). Adalind was never going to be safe but as long as Conrad got what he wanted, nothing deadly would happen to her. And from what we saw of Conrad, he was very strong so even if Adalind decided to use her powers against him, she would have ended up dead and that would have left her children with BC, a worse fate than if she does what they tell her (to an extent) while making sure she's close to both her children.
Sean may have put her in this fake relationship but the cursed ring is keeping her there (for now). I think Sean would still need Adalind and their fake relationship because clearly they are/were aiming much higher than just him being mayor of Portland but that's story is over with Conrad's death it seems. I think they initially thought she'd come willingly until they realised she'd never leave Nick and so resorted to force (and Diana). Adalind was never going to be safe but as long as Conrad got what he wanted, nothing deadly would happen to her. And from what we saw of Conrad, he was very strong so even if Adalind decided to use her powers against him, she would have ended up dead and that would have left her children with BC, a worse fate than if she does what they tell her (to an extent) while making sure she's close to both her children.